The propulsion system found on industrial and agricultural vehicles consists of a pair of longitudinally spaced apart wheel structures which are arranged on opposite sides of the vehicle's chassis, the latter being driven by a pair of endless, substantially inextensible tracks, each having an inner surface and an outer surface. These endless tracks consist of a flexible body formed of rubber material and are usually reinforced with one or more layers of fabric or steel material. The body includes series of longitudinally spaced profiles upon the outer surface thereof to provide traction to the vehicle and a series of longitudinally spaced drive lugs integrally moulded to the inner surface of the track to guide the track relative to driving and tracking wheels on the vehicle. The driving sprocket have drive teeth or bars positioned around the outer periphery thereof and positioned to engage the drive lugs on the inner surface of the track.
One such track structure is illustrated and described in U.S. Pat. No. 5,279,378 issued Jan. 18, 1994 to Caterpillar Inc. Similar tracks are also illustrated and described in U.S. Pat. No. 5,005,922 issued Apr. 9, 1991 to Edwards & Co. and U.S. Pat. No. 5,984,438 issued Nov. 16, 1999 to Tsunoda et al.
Drive lug deterioration due to the excessive torque transmitted to the drive lug and fatigue have been observed on many tracks resulting in drive lug delamination, chunking or even broken lugs.